Speaker John A. Boehner and House Majority Leader Eric Cantor have backed President Barack Obama's plan to strike Syria, giving the president a major lift as the White House conducts an all-out push to get lawmakers on board ahead of votes expected next week.

Boehner emerged from a White House briefing on Syria with Obama this morning prepared to, in his words, "support the president's call to action."

"And I believe my colleagues should support the president's call to action," the Ohio Republican added. He joined Minority Leader Nancy Pelosi, D-Calif., who had already backed a strike against Syria.

"The use of these [chemical] weapons has to be responded to and only the United States has the capability and capacity to stop Assad and warn others around the world that this type of behavior will not be tolerated," Boehner said.

Cantor also released a statement Tuesday morning that said he intends to "vote to provide the President of the United States the option to use military force in Syria."

"While the authorizing language will likely change, the underlying reality will not," the Virginia Republican said, also noting that "there are differing opinions on both sides of the aisle" and "it is up to President Obama to make the case to Congress and to the American people that this is the right course of action, and I hope he is successful in that endeavor."

While some in Congress have criticized Obama's drawing of a "red line" with Syria on chemical weapons, Cantor stood by it.

"A failure to act when acting is in America's interests and when a red line has been so clearly crossed will only weaken our ability to use diplomacy, economic pressure, and other non-lethal tools to remove Assad and deter Iran and other aggressors," he said.

Pelosi reiterated her support for military action and said she would seek to persuade other lawmakers to do the same to take on Bashar al-Assad.

"People say, 'Well, he killed 100,000 people. What's the difference with this 1,400?' With this 1,400, he crossed a line with using chemical weapons. President Obama did not draw the red line. Humanity drew it decades ago, 170-some countries supporting the convention on not using chemicals — chemical warfare."

She said that the United States needed "to send a very clear message to those who have weapons of mass destruction of any variety that — that they should forget about using them."

"Members have to decide are they willing — do they want to ignore the fact that this humanitarian disaster took place or not? And then there's the larger issue of Syria's behavior if they get away with it."

And the whipping operation still won't be a slam dunk, as noted by Boehner spokesman Brendan Buck.

“Everyone understands that it is an uphill battle to pass a resolution, and the speaker expects the White House to provide answers to members’ questions and take the lead on any whipping effort," Buck said. "All votes authorizing the use of military force are conscience votes for members, and passage will require direct, continuous engagement from the White House."